WO2013183074A1

WO2013183074A1 - Seebeck effect thermoelectric module

Info

Publication number: WO2013183074A1
Application number: PCT/IT2013/000156
Authority: WO
Inventors: Giovanni Facchiano; Roberto Quintili
Original assignee: Pesaresi Stefano; PAMPANI Paola; PERUGINI Chiara
Priority date: 2012-06-06
Filing date: 2013-06-03
Publication date: 2013-12-12
Also published as: ITRM20130032A1

Abstract

The present invention relates to a thermoelectric module (13) having a first face (17) and a second face (18), opposed with respect to said first face (17), and characterized in that it comprises at least a Seebeck effect cell element (20; 21; 22), for converting thermal energy into electric energy, said cell element (20; 21; 22) comprising a first face (700) and a second face (800), opposed to said first face (700), said first and second faces (700, 800) being respectively faced toward said first face (17) and toward said second face (18) of said thermoelectric module (13), and at least a thermoelectric element (1), having a first side (70) and a second side (80), opposed with respect to said first side (70), said first and second sides (70, 80) being respectively provided in correspondence of said first and second faces (700, 800) of said cell element (20; 21; 22), said at least one thermoelectric element (1) comprising a first film (2), a second film (3) and at least a conductive layer (4), said at least a conductive layer (4) comprising a plurality of first and second conductive elements (5, 6), said plurality of first and second conductive elements (5, 6) being in contact each other in a plurality of first and second junction points (7, 8) to obtain Seebeck effect, each junction point (7, 8) being provided respectively along said first and said second side (70, 80) of said at least one thermoelectric element (1), and in that said thermoelectric module (13) further comprises a thermal glass (15), a housing (16) for said at least one cell element (20; 21; 22) and a frame (14) for said thermal glass (15) and said housing (16).

Description

SEEBECK EFFECT THERMOELECTRIC MODULE

The present invention relates to a Seebeck effect thermoelectric module.

More specifically, the present invention is included within the field of recovery energy produced by renewable sources.

Particularly, the present invention is included within the field of electric production deriving from exploitation of sun energy, geothermic energy and energy from other heat sources produced by wastes of industrial systems, in combination with Seebeck effect thermoelectric modules.

Seebeck effect principle about metal thermoelectricity is known since 1821. In the following years, studies and development of new metallic alloys permitted improving efficiency of said effect, obtaining both a better electric and thermal conductivity.

However, applications available on the market permit obtaining a very low amount of electric energy for each unit of thermal energy, thus being characterized by very low efficiencies, thus not justifying high costs of employed materials.

In fact, in the known art, higher efficiencies are obtained employing very expensive conductive materials, which are also difficult to be found.

It is therefore well clear the needing of developing technical solutions permitting improving electrical yielding of available thermal energy in this kind of systems.

Therefore, it object of the present invention that of realizing a Seebeck effect thermoelectric module overcoming the above mentioned drawbacks and permitting reducing costs, not requiring the use of expensive materials.

Another advantage is that of permitting an easy replacement of single components, particularly of single cell elements, in case of damaging, without jeopardizing the whole module, with a consequent energy saving.

It is subject matter of the present invention a thermoelectric module having a first face and a second face, opposed with respect to said first face, and characterized in that it comprises at least a Seebeck effect cell element, for converting thermal energy into electric energy, said cell element comprising a first face and a second face, opposed to said first face, said first and second faces being respectively faced toward said first face and toward said second face of said thermoelectric module, and at least a thermoelectric element, having a first side and a second side, opposed with respect to said first side, said first and second sides being respectively provided in correspondence of said first and second faces of said cell element, said at least one thermoelectric element comprising a first film, a second film and at least a conductive layer, said at least a conductive layer comprising a plurality of first and second conductive elements, said plurality of first and second conductive elements being in contact each other in a plurality of first and second junction points to obtain Seebeck effect, each junction point being provided respectively along said first and said second side of said at least one thermoelectric element, and in that said thermoelectric module further comprises a thermal glass, a housing for said at least one cell element and a frame for said thermal glass and said housing.

Particularly, according to the invention, said thermal glass and said housing can be spaced each other so as to realize a heat acquisition chamber.

Still according to the invention, said at least one cell element can be introduced for about 50% between said glass and said housing.

Always according to the invention, said glass and said housing can be spaced of about 10 mm.

Furthermore, according to the invention, said thermoelectric module can comprise a ventilation system for said first face or for said second face of said thermoelectric module, so as to increase thermal difference between said first face and said second face of said thermoelectric module.

Preferably, according to the invention, said thermoelectric module can comprise a plurality of cell elements connected each other in series or in parallel.

Further, according to invention, said at least a cell element can comprise a plurality of thermoelectric elements juxtaposed each other.

Still according to the invention, said at least one thermal element of said at least one cell element can have a plurality of tracts, having the same of different length each other, said tracts being S shaped, so as to juxtapose each other. Always according to the invention, said at least one cell element can comprise at least a bobbin wound thermoelectric element.

Particularly, according to the invention, said at least one thermoelectric element of said at least one cell element can be wound as a bobbin on a support to realize a bobbin winding.

Further, according to the invention, said support can be comprised of metal, preferably aluminum.

Still, according to the invention, said plurality of first conductive elements can be comprised of constantan and said plurality of second conductive elements can be comprised of nickel.

Finally, according to the invention, said first and second films can be comprised of polyamide.

The present invention will be now described, for illustrative, but not limitative, purposes, making reference to its preferred embodiments, with specific reference to the figures of the enclosed drawings, wherein:

figure 1 shows an exploded perspective view of a thermoelectric module according to the invention comprising a first embodiment plurality of Seebeck effect cell elements;

figure 2 shows a front perspective view of a thermoelectric element;

figure 3 shows a top view of thermoelectric element of figure 2 open;

figure 4 shows a front perspective view or thermoelectric element of figure 2;

figure 5 shows a lateral perspective view of thermoelectric element of figure 2;

figure 6 shows a perspective view of the first embodiment of cell element according to the invention;

figure 7 shows a perspective view of support of cell element of figure 6;

figure 8 shows a front view of cell element of figure 6; figure 9 shows a lateral section view taken along line VIII-VIII off figure 8;

figure 10 shows a lateral view of cell element of figure 6;

figure 11 shows a perspective view of a second embodiment of the cell element according to the invention; figure 12 shows a perspective view of a third embodiment of cell element according to the invention; and

figure 13 shows a perspective view of a thermoelectric module according to the invention comprising a plurality of cell elements according to figure 11 or figure 12.

A thermoelectric module according to the present invention is represented in figure 1 , indicated by reference number 13. Said thermoelectric module 13 comprises a plurality of Seebeck effect cell elements 20, according to a first embodiment. Said thermoelectric module 13, preferably with a surface of 1 m², comprises a metal frame 14, a thermal glass 15 and a housing 16 for said plurality of cell elements 20, preferably twenty-five.

Said Seebeck effect cell elements 20 provides a first face 700 and a second face 800, opposed with respect to said first face 700, and are housed within said housing 16 so as to have all their first faces 700 faced toward a first face 17 of module 13 and all second faces 800 faced toward a second face 18 opposed with respect to said first face 17 of module 13.

Said cell elements 21 are connected each other by electric cables, in series or in parallel, thus creating an electric circuit, to obtain a current tension and intensity suitable for the application field, and particularly, they can be combined with an inverter.

Subjecting one the two faces 17 and 18 o module 13 to a heat source, a so called hot face and a so called cold face are obtained. Temperature difference between said two faces 17 and 18 generates, by Seebeck effect, a potential difference between ends of electric circuit, thus producing a conversion from thermal energy into electric energy.

Further, said cell elements 20 are preferably inserted or about 50% between glass 15 and housing 16, to permit an easy dissipation of heat. Glass 15 ad housing 16 can be spaced of about 10 mm, to create a heat acquisition chamber.

Further, a forced ventilation system (not shown) can be provided in correspondence of one of said two faces 17 or 18 of module 13, preferably cold face, in order to further increase temperature difference between two module faces, thus increasing efficiency of the same module and thus electric energy production. Each cell element 20 provides at least a thermoelectric element 1 (shown in figures 2 - 5) comprising a first 2 and a second 3 film and a conductive layer 4 comprising a plurality of thermocouples, each thermocouple comprising a first 5 and a second 6 conductive element. Said first 5 and second 6 conductive element contact each other in a first junction point 7 and said plurality of thermocouples being in contact with the following one in a second junction point 8.

In the embodiment described, said first conductive elements 5 are parallel linear elements, provided on said first film 2 and substantially equidistant each other, while said second conductive elements 6 are parallel linear elements, provided on said second film 3 and substantially equidistant each other, so that first ends of said first 5 and second 6 conductive elements contact each other on said first junction point 7 in correspondence of the first side 70 of thermoelectric element 1 ad second ends of said first 5 and second 6 conductive elements contact each other on said second junction point 8 in correspondence of the second side 80 of thermoelectric element 1.

By subjecting one of the two sides 70, 80 to a heat source, a so called hot face and an opposed so called cold face are obtained. Temperature difference between said two sides 70 and 80, by Seebeck effect, generates a potential difference between ends of said plurality of thermocouples, causing a conversion from thermal energy into electric energy.

In further embodiments, said plurality of thermocouples of conductive elements can have different geometries, provided that two contact ends are present.

Said pair of conductive elements 5 and 6 can be comprised of constantan and nickel, or of constantan and copper or of other metallic materials already employed in the thermocouple field.

Said first 2 and second 3 films are preferably comprised of polyamide or of another material having similar mechanical features.

Preferably, said conductive elements 5 and 6 have a thickness between 25 and 50 micron.

Further, preferably, said films 2 and 3 have a thickness between 80 and 100 micron.

Method for realizing said thermoelectric element provides the following steps:

a) coupling said films 2 and 3 with said conductive elements 5 and 6, so that said first and second conductive elements 5 and 6 are externally protected by said films 2 and 3, being each other in contact in correspondence of said two junction points 7 and 8.

Said step a) can comprise the following sub-steps:

b1) coupling of said first conductive elements 5 with said first film 2;

b2) coupling said second conductive elements 6 with said second film 3;

b3) juxtaposing said films 2 and 3 so that said two conductive elements 5 and 6 contact each other in correspondence of two junction points 7 and 8, being externally protected by said films 2 and 3.

As an alternative, said step a) can comprise the following steps: c1) coupling said first conductive elements 5 with said first film

2;

c2) coupling said second conductive elements 6 with said first conductive elements 5, so that said first and second conductive elements

5 and 6 contact each other in correspondence of two junction points 7 and

8;

c3) juxtaposing said second film 3 and said first film 2, so that said first and second conductive elements 5 and 6 are externally protected by said films 2 and 3.

Still as an alternative, said step a) can comprise the following steps:

d1 ) coupling said first conductive elements 5 with said second conductive elements 6, so as to contact each other in correspondence of two junction points 7 and 8;

d2) coupling said two films 2 and 3 with said conductive elements 5 and 6, so that said first and second conductive elements 5 and

6 are externally protected by said films 2 and 3.

Said methods are realized by known rotative machines employed for realizing printed boards, permitting creating long bands.

Taking into consideration preferred embodiments of this embodiment, it is possible introducing about 500 - 600 thermocouples for each meter.

A thermoelectric element 1 as described in the above is shown in figures 6 - 10, wound as a bobbin on a support 9, creating a first embodiment of cell element 20, hosed within thermoelectric element 13 of figure 1. Aid support 9 has an axis 10, about which thermoelectric element 1 is wound, and two plates 11 and 12, each one fixed on a relevant end of said axis 10. Said support 9 is comprised of conductive material, preferably aluminum, thanks to its optimum features of thermal conductivity.

Cell element 20 advantageously comprises a very high density of conductive elements 5, 6 thermocouples within a reduced volume.

Said cell element 20 comprises a first face 700 created by winding of first side 70 of thermoelectric element 1 in correspondence of the first plate 11 of support 9, and a second face 800 realized by winding of second side 80 of thermoelectric element 1 in correspondence of second plate 12 of support 9.

Subjecting one of the two faces 700 or 800 of cell element 20 to a heat source, a so called hot face and a so called cold face, opposed with respect to the hot one, are obtained. Temperature difference between said two faces, by Seebeck effect, generates a potential difference between ends of said plurality of thermocouples contained in said cell element 20, causing a conversion from thermal energy into electric energy.

Said bobbin support 9 preferably has a diameter between 200 mm and 500 mm.

Particularly, a band thermoelectric element 1 long about 522 m, comprising about 310,000 thermocouples is wound on a bobbin support having a diameter of 200 mm.

Further, doubling diameter of support, number of thermocouples is multiplied four times, so that, a support having a diameter of 500 mm can contain up to two millions of thermocouples, thus improving spaces and increasing thermal energy transformed into electric energy.

Manufacturing method of said cell elements 20 provides, after said step a), the following step:

e) winding as a bobbin the thermoelectric element 1 about said support 9.

Making reference to figure 11 , it is observed a second embodiment of cell element 21. Said cell element 21 comprises a plurality of thermoelectric elements 1 , as described in figures 2 - 5, juxtaposed so as to create a substantially parallelepiped shape.

In this embodiment, thermoelectric elements 1 are juxtaposed so that first sides 70 of each thermoelectric element 1 create first face 700 of said first cell element 21 , and second sides 80 of each thermoelectric element 1 realizes a second face 800 of said cell element 21.

Advantageously, cell element 21 has a high density of conductive element 5, 6 thermocouples on first and second faces 700 and 800 within a reduced volume.

Subjecting one of the two faces 700 or 800 of cell element 21 to a heat source, a so called hot face and an opposed cold face are obtained. Temperature difference between said two faces of cell element 21 , by Seebeck effect, generates a potential difference between ends of said plurality of thermocouples contained within each thermoelectric element, causing a conversion from thermal energy into electric energy.

Manufacturing method of said cell element 21 provides, after step a), the following step:

f) juxtaposing a plurality of thermoelectric elements 1. A third embodiment of cell element 22 according to the invention is shown in figure 12, comprising a thermoelectric element 1 , having tracts of same length or of different length each other, said tracts 23 being S folded so as to be juxtaposed each other.

In this embodiment, each one of said plurality of tracts 23 of said at least one thermoelectric element 1 is juxtaposed on the others so that first folded side 70 of said at least one thermoelectric element 1 realizes a first face 700 of said cell element 22, and second folded side 80 of said at least one thermoelectric element 1 realizes a second face 800 of said cell element 22.

The above advantageously permits having a high density of conductive elements 5, 6 thermocouples on first 700 and second 800 faces within a reduced volume.

Subjecting one of the two faces 700 or 800 of cell element 22 to a heat source, a so called hot face and an opposed cold face are obtained. Temperature difference between said two faces 700 and 800 of cell element 22, by Seebeck effect, generates a potential difference between ends of said plurality of thermocouples contained within each thermoelectric element 1 , causing a conversion from thermal energy into electric energy.

Manufacturing method of said cell element 22 provides, after step a), the following step: g) folding each tract 23 of said at least one thermoelectric element 1 , so that they are juxtaposed each other.

A thermoelectric module 13 according to the invention is shown in figure 13, said module 13 comprising a plurality of cell elements 21 or 22 according to the second or third embodiment. Said thermoelectric module 13 comprises a metal frame 14, a thermal glass 15 and a housing 16 for said cell elements 21 or 22.

Said cell elements 21 or 22 are housed in said housing 16 so that all first faces 700 are faced toward a first face 17 of module 13 and all second faces 800 are faced toward a second face 18 opposed with respect to the first face 17 of module 13. Said cell elements 21 Or 22 are connected in series or in parallel by electric cables, thus realizing an electric circuit, to obtain suitable current tension an intensity suitable for the application field, and particularly can be used in combination with an inverter.

Subjecting one of the two faces 17 or 18 of module 13 to a heat source, a so called hot face and an opposed cold face are obtained. Temperature difference between said two faces 17 and 18, by Seebeck effect, generates a potential difference between ends of electric circuit, causing a conversion from thermal energy into electric energy.

Further, cell elements 21 , 22 are preferably inserted for about 50% between glass 15 and housing 16, to permit an easy dissipation of heat. Glass 15 and housing 16 can be spaced of about 10 mm to realize a heat dissipation chamber.

Also in this case, a forced ventilation system (not shown) can be provided in correspondence of one face of thermoelectric module, preferably cold face, in order to further increase temperature difference between two module faces, thus increasing efficiency of the same module and thus electric energy production.

An advantage of thermoelectric module according to the invention is that of obtaining a high efficiency thermoelectric energy generator at low costs.

A further advantage is that of permitting an easy replacement of single components, particularly of single thermoelectric elements, in case of damaging, without jeopardizing the whole module, with a consequent cost saving. The present invention has been described, for illustrative, but not limitative, purposes, with particular reference to its preferred embodiments, but it is to be understood that modifications and/or variations can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.

Claims

1. Thermoelectric module (13) having a first face (17) and a second face (18), opposed with respect to said first face (17), and characterized in that it comprises at least a Seebeck effect cell element (20; 21 ; 22), for converting thermal energy into electric energy, said cell element (20; 21 ; 22) comprising a first face (700) and a second face (800), opposed to said first face (700), said first and second faces (700, 800) being respectively faced toward said first face (17) and toward said second face (18) of said thermoelectric module (13), and at least a thermoelectric element (1), having a first side (70) and a second side (80), opposed with respect to said first side (70), said first and second sides (70, 80) being respectively provided in correspondence of said first and second faces (700, 800) of said cell element (20; 21 ; 22), said at least one thermoelectric element (1) comprising a first film (2), a second film (3) and at least a conductive layer (4), said at least a conductive layer (4) comprising a plurality of first and second conductive elements (5, 6), said plurality of first and second conductive elements (5, 6) being in contact each other in a plurality of first and second junction points (7, 8) to obtain Seebeck effect, each junction point (7, 8) being provided respectively along said first and said second side (70, 80) of said at least one thermoelectric element (1), and in that said thermoelectric module (13) further comprises a thermal glass (15), a housing (16) for said at least one cell element (20; 21 ; 22) and a frame (14) for said thermal glass (15) and said housing (16).

2. Thermoelectric module (13) according to preceding claim, characterized in that said thermal glass (15) and said housing (16) are spaced each other so as to realize a heat acquisition chamber.

3. Thermoelectric module (13) according to preceding claim, characterized in that said at least one cell element (20; 21; 22) is introduced for about 50% between said glass and said housing.

4. Thermoelectric module (13) according to one of preceding claims, characterized in that said glass (15) and said housing (16) are spaced of about 10 mm.

5. Thermoelectric module (13) according to one of preceding claims 1 - 4, characterized in that it comprises a ventilation system for said first face (17) or for said second face (18) of said thermoelectric module (13), so as to increase thermal difference between said first face (17) and said second face (18) of said thermoelectric module (13).

6. Thermoelectric module (13) according to one of preceding claims, characterized in that it comprises a plurality of cell elements (20;

21 ; 22) connected each other in series or in parallel.

7. Thermoelectric module (13) according to one of preceding claims, characterized in that said at least one cell element (20; 21 ; 22) comprises a plurality of thermoelectric elements (1) juxtaposed each other.

8. Thermoelectric module (13) according to one of preceding claims 1 - 6, characterized in that said at least one thermoelectric element (1) of said at least one cell element (20; 21; 22) has a plurality of tracts (23), having the same of different length each other, said tracts being S shaped, so as to juxtapose each other.

9. Thermoelectric module (13) according to one of preceding claims 1 - 7, characterized in that said at least one cell element (20) comprises at least a bobbin wound thermoelectric element (1).

10. Thermoelectric module (13) according to one of preceding claims, characterized in that said at least one thermoelectric element (1) of said at least one cell element (20) is wound as a bobbin on a support (9) to realize a bobbin winding.

11. Thermoelectric module (13) according to one of preceding claims, characterized in that said support (9) is comprised of metal, preferably aluminum.

12. Thermoelectric module (13) according to one of preceding claims, characterized in that said plurality of first conductive elements (5) is comprised of constantan and said plurality of second conductive elements (6) is comprised of nickel.

13. Thermoelectric module (13) according to one of preceding claims, characterized in that said first and second films (2, 3) are comprised of polyamide.